How much you enjoy “I Origins” may well depend on whether you think lines like “Maybe the eye really is a window to the soul” are cliched.

It’s hard to argue that they aren’t, and writer and director Mike Cahill, despite a mighty effort, never really makes a convincing case otherwise. This doesn’t mean there aren’t some pleasures in the film, which looks fantastic and features the intriguing Brit Marling in its cast. But the struggle between faith and reason somehow gets sidetracked, resulting in a sometimes silly, too-obvious journey. (At least Cahill doesn’t beat us over the head too badly with the ending, leaving it open to interpretation, though only a little.)

Ian (Michael Pitt) is a genetic researcher who has been obsessed with eyes since he was a child. He works with his lab partner, Karen (Marling), trying to jump-start the evolution of sight in blind worms. This, Ian is certain, will prove that evolution, and not a higher power, set the world in motion.

Ian is into his work, but Karen is obsessed, happiest while locked in the lab, which is fortunate for Ian but not for the rest of us, as her work keeps Karen (and Marling) captive for a sizable chunk of the movie.

After a chance meeting at a Halloween party results in a bathroom tryst with a mysterious woman (wearing a mask, so he sees only her eyes), Ian becomes obsessed with finding her again. The iris is as distinctive as a fingerprint, we learn, so he uses this knowledge to search for her.

But he finds her by way of a weird phenomenon in which the number 11 keeps popping up combined with a billboard ad for French perfume. The woman, Sofi (Astrid Berges-Frisbey), is spiritual by nature, albeit in an obtuse way that involves speaking rapturously about white peacocks and statues that cry. But she earnestly believes she and Ian are soulmates, and he is not opposed to the idea, despite his lack of faith in a spiritual life. They spend a fair amount of time in bed discussing this sort of thing, while Karen toils away in the lab.

Developments best not revealed eventually lead Ian to India, where he again searches for a specific pair of eyes (and again, a billboard comes into play). There are a couple of twists that are somewhat satisfying, and more that are not. Cahill has good ideas (he and Marling co-wrote his last feature, “Another Earth”), and his actors hold nothing back in trying to achieve his vision.